1. Field of the Invention
The present invention relates to image processing, and more specifically to cross fading in image processing.
2. Description of the Related Art
Image processing of digital images can include producing effects in video and still images. For example, one effect called cross fading permits smooth blending and transitions between images. Typically, calculations for cross fading can consume many processing cycles. For example, a desktop computer performing cross fading calculations generally does not burden resources of the desktop computer, such as memory and power. However, in a mobile device, cross fading calculations can consume too much memory and too many processing cycles. Further, the mobile device has limited battery power. Thus, when performing processor-intensive cross fading calculations on the mobile device, battery life suffers.
Another deleterious effect caused by performing cross fading calculations on the mobile device is increased bus traffic between the processor and an image processing processor. When the image processing processor performs cross fading calculations, the increased bi-directional bus traffic to and from the processor can compete with other data on the bus, thereby causing the mobile device to perform inefficiently. To overcome these limitations when performing cross fading calculations on the mobile device, solutions can include increasing memory and increasing bus lines.
However, because of limited real estate on the mobile device, it is difficult and expensive to design the mobile device to have ever-increasing memory and bus lines. For example, the memory of the mobile device can store two images for cross fading, such as an image of a dog and an image of a cat. During the transition between the two images, a third image, such as a combined image of the dog and cat is typically stored in memory. However, with references to devices with limited memory capacity, one of the original two images may be overwritten by the third image. Overwriting the original image causes the image to be irretrievably lost.
Accordingly, what is needed is a method and apparatus for performing cross fading calculations in the mobile device, while maintaining the existing resources and operating efficiency of the mobile device.